It is well known that printed circuit (PC) boards used in electronic devices can be miniaturized by using surface mountable devices. Most electronic components such as capacitors, resistors, inductors, diodes, transistors, etc, are readily available in surface mountable packages. As is also known, surface mountable power devices, such as power diodes and transistors, generate heat which, if not dissipated, could destroy the component. One common approach to protect the surface mountable power device from overheating is to use the ground plane, or similar thermally conductive area, of the PC board as a heat sink. This typically provides adequate dissipation of the heat generated, but requires a relatively significant amount of board space which increases the size of the PC board.
An alternative to using the PC board as a heat sink is to use larger packages than a surface mountable package. Such larger packages, such as a TO-220 or a TO-218 package, usually have a through mounting hole which can be mounted to a separate heat sink. This approach provides greater heat dissipation than the abovementioned ground plane approach, however, it is not without costs. One disadvantage of using separate heat sinks is the amount of board space required. With such a large amount of board space required, optimum miniaturization of an electronic component cannot be realized. Another disadvantage is that the heat sink assembly has to be soldered to the PC board after the majority of the board has been wave soldered. As is known, post wave solder assembly, such as is required with separate heat sinks, consistently produce a higher defect rate than PC board without such assemblies. Therefore, a need exists for a heat sinking apparatus that provides adequate heat dissipation for surface mountable power devices and overcomes the above mentioned problems.